That's a good question. Redfield or somebody used to have a rectangle shaped objective lense that I guess they marketed for having a wider angle of view. I don't recall them being on the market for the past 20-25 years.
All I can come up with is maybe regular veiw/angle scopes are cheaper, quicker, and/or easier to manufacture. I guess if enough folks spoke up and made a manufacturer think there's a demand, then I guess that in a year or two that would be the rage amongst all scope builders. Maye if instead of a "Wide Angle or Wide View" scope, they called it a "Zombie Special", or "Super Tactical", or "Sniper Operator Spec-Ops Tactical Super Zombie Killer Scope" it would probably get voted best scope of the year by 40 different gun rags... 50 or more if they could squeeze "Turbo Ninja" in there somewhere.
Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day)
I'm going to use the words "clip" and "Long Colt" every chance I get. It grinds my gears to see new members attacked when we all know dang good and well what's being refered to.